OTRC: Justin Timberlake attends the Marine Corps Ball

Justin Timberlake kept his promise to attend the Marine Corps Ball on Saturday, much to the delight of his date, female Marine Kelsey De Santis.

The "In Time" star donned a black tuxedo to the event and was picked up at his hotel by Corporal de Santis, who was wearing her Marine Corps dress uniform. De Santis, who is the only female at the Martial Arts Center for Excellence (MACE) at Marine Corps Base Quantico, later changed into a low-cut silver mini dress.

There is no word yet on whether the singer-turned-actor took up De Santis' challenge of a dance-off, but the Marine was convinced she would take down Timberlake.

"My friends keep saying, 'Dance-off!' They know about my skills," De Santis told Access Hollywood. "I honestly don't think he'll be able to keep up with my group of people... I don't think he'll be able to keep up with us."

Timberlake accepted his invitation to attend the Marine Corps Ball in July, with the encouragement of his "Friends with Benefits" co-star Mila Kunis, who had already accepted an invitation.

The Virginia-based female Marine also joked that she wouldn't turn down a midnight kiss.

"Of course, I'm single!" De Santis continued. "I guess that's all up to JT and what his plans are... I would never force anything upon him or anything like that!"

De Santis asked Timberlake to accompany her to the Marine Corps Ball on November 12 in Washington D.C. and said in her YouTube invite, "If you can't go, all I can say is cry me a river." At a recent press conference promoting his upcoming romantic comedy, Timberlake was asked if he would accept the servicewoman's invitation to the ball and the actor said, "I'll tell you what, I accept."

"But not because she shouted out one of my songs, which I do love," he joked. "And not because she had all those beefcake military guys behind her to intimidate me."

Timberlake said that he accepted the invite because he was flattered to be asked.

"I don't get asked out -- ever," Timberlake said. "So I was very flattered by that... If my schedule works out to do it, I'd love to do it. It's an honor."